Add exception handler cache to isolate

runtime/vm/raw_object.h

Index: runtime/vm/raw_object.h
diff --git a/runtime/vm/raw_object.h b/runtime/vm/raw_object.h
index 2f2cf6046e504220bbddb1ff01ea043dd8b8f9cd..479e61a83e5f685135e38d7b6230fc684c41efad 100644
--- a/runtime/vm/raw_object.h
+++ b/runtime/vm/raw_object.h
@@ -1403,16 +1403,6 @@ class RawLocalVarDescriptors : public RawObject {
 
 
 class RawExceptionHandlers : public RawObject {
- public:
-  // The index into the ExceptionHandlers table corresponds to
-  // the try_index of the handler.
-  struct HandlerInfo {
-    uint32_t handler_pc_offset;  // PC offset value of handler.
-    int16_t outer_try_index;     // Try block index of enclosing try block.
-    int8_t needs_stacktrace;     // True if a stacktrace is needed.
-    int8_t has_catch_all;        // Catches all exceptions.
-  };
-
  private:
   RAW_HEAP_OBJECT_IMPLEMENTATION(ExceptionHandlers);